Separation of CO2 from power plant flue gas and other gas mixtures that result from industrial processes and other fixed point sources is critical for reducing greenhouse gas emissions, and especially such emissions due to electricity generation. Technologies exist today to remove CO2 from flue gas, such as absorptive technologies based on amines, but these technologies are costly and significantly reduce overall power plant efficiency. An additional challenge of today's CO2 separation processes is that subsurface geologic structures must be present and able to receive CO2. Locations which do not have suitable geologic formations will not be able to sequester the CO2, even if it can be separated from the flue gas mixture. Thus, there exists a need to develop an improved technology capable of not only removing CO2 from flue gas or other industrially produced waste gas mixtures, but also providing the captured CO2 in a form, such as a solid hydrate, that is amenable to sequestration by methods other than injection into subsurface geologic formations.
U.S. Pat. No. 5,434,330 describes a process for separating clathrate forming gases by first contacting a gaseous stream with an aqueous solvent to form a hydrate suspension. The clathrate forming gases are then selectively recovered by exposing the hydrate suspension (or the separated hydrate) to increased temperature and/or reduced pressure.
US20130012751 describes a process by which the corrosive elements of a gas stream (e.g. CO2, H2S) can be separated from hydrocarbon gases in a hydrate-based separator using a similar approach as outlined in the U.S. Pat. No. 5,434,330. The process yields a gas product, e.g. a purified natural gas product that is less corrosive due to removal of H2S and CO2 from the natural gas.